Nintendo NX 4K... thanks to Pikmin 4.

[Soundwave]

4K is 9x the pixels of 720p, so to make a game identical to Pikmin 3 run at 4K, you would need a system 9x more powerful.

Assuming the Wii U is 300 GFLOPS or so, that would put the requirement for a Pikmin 4K using identical assets as the Wii U version at 2.7 TFLOPS.